0:00
9:51
Spol 15 sekunder tilbage
Spol 15 sekunder frem

Are things only worth what people are willing to pay for them? Tim Harford explains why a method of buying and selling that originated in ancient times has endured to the present day, and is now underpinning the success of some of the internet's most powerful brands.

Flere episoder fra "50 Things That Made the Modern Economy"